Polystyrene is a polymer made from the monomer styrene, a liquid hydrocarbon that is commercially manufactured from petroleum. At room temperature, polystyrene is normally a solid thermoplastic, but can be melted at higher temperature for molding or extrusion, then resolidified. Styrene is an aromatic monomer, and polystyrene is an aromatic polymer.
Polystyrene is naturally clear, exhibits excellent chemical resistance and is more resistant to irradiation than is PE or PP. Electrical resistance is also good. This, plus the ease with PS can be painted or shielded, has led to extensive electrical and electronic applications. PS is also often used in appliances and housings. Special high gloss and high impact grades are also widely available. Pure solid polystyrene is a colorless, harder plastic with limited flexibility which can be cast into molds with fine detail. Polystyrene can be transparent or can be made to take on various colors. It is economical and is used for producing plastic model assembly kits, plastic cutlery, CD “jewel” cases, and many other objects where a fairly rigid, economical plastic of any of various colors is desired.
The ubiquitous use of PS in industry makes it a prime material candidate for a variety of applications where the PS comprises some or all of a surface. One of the drawbacks to using PS as surface is that materials that bind to PS are specific and lack flexibility as binding agents. So for example where a new coating for PS is desired, a new search for a PS binding molecule with the desired property must be conducted. The resulting search is costly in both time and resources and not guaranteed to be successful. A system that is flexible and can be easily tailored for a variety of materials to be bound to PS is needed. The use of peptides as linkers or binders to PS offers some potential in this regard.
Peptides having a binding affinity to polymer and plastic surfaces are known. For example, Adey et al., (Gene 156:27-31 (1995)) describe peptides that bind to polystyrene and polyvinyl chloride surfaces. Additionally, peptides that bind to polyurethane (Murray et al., U.S. Patent Application Publication No. 2002/0098524), polyethylene terephthalate (O'Brien et al., copending and commonly owned U.S. Patent Application Publication No. 2005/0054752), and polystyrene, polyurethane, polycarbonate, and nylon (Grinstaff et al., U.S. Patent Application Publication No. 2003/0185870) have been reported. However, the use of such peptides to target PS surfaces has not been described.
There remains a need therefore for a peptide based reagent that binds PS that offers flexibility in bring a wide variety of materials to the PS surface with minimum investment in redesign. Applicants have solved the stated problem by providing peptide reagents comprising PS binding peptides (PSBP). The PS binding peptides of the invention may be modified with other functional or binding peptides allowing for the delivery of benefit agents to the PS surface or for the use of the reagents to adhere PS containing surfaces.